Arrangement in handtools, such as pliers, pincers and the like

ABSTRACT

A handtool comprising a pair of leg members pivotally attached together intermediate their ends, the leg members having mutually opposed jaws for acting on a workpiece disposed on one side of the pivot axis and handles for operating said jaws disposed on the other side of the pivot axis. Guide means for precisely aligning the jaws laterally with respect to one another are carried by the leg members. The guide means are separated and spaced from the pivot joint, a distance not less than the distance from the pivot joint to the outer ends of the jaws, and the leg members are laterally separated between the pivot joint and the guide means.

United States Patent [72] Inventor Bengt Bruno Brunosson Eskilstuna, Sweden [211 App]. No. 707,631 [22] Filed Feb. 23, 1968 [45] Patented June 8, 1971 [73] Assignee A B Baheo Stockholm, Sweden [54] ARRANGEMENT IN HANDTOOLS, SUCH AS PLIERS, PINCERS AND THE LIKE 2 Claims, 2 Drawing Figs.

[52] US. Cl 81/415, 128/318 [51] Int. Cl 1125b 7/00 [50] FieIdotScarch 81/415, 417, 416, 427, 3.6, 5.1; 30/261, 266, 268, 258, 175,193, 254,186, 257,191; 1281321, 322, 318, 326, 340, 346; 72/409; 29/268 [56] References Cited UNITED STATES PATENTS 662,178 11/1900 Truax 128/340 FOREIGN PATENTS 49,336 10/1889 Germany 1.

OTHER REFERENCES Primary Examiner-Robert C. Riordon Assistant Examiner-Roscoe V. Parker, Jr. Attorney-Birch, Swindler, McKie & Beckett ABSTRACT: A handtool comprising a pair of leg members pivotally attached together intermediate their ends, the leg members having mutually opposed jaws for acting on a workpiece disposed on one side of the pivot axis and handles for operating said jaws disposed on the other side of the pivot axis. Guide means for precisely aligning the jaws laterally with respect to one another are carried by the leg members. The guide means are separated and spaced from the pivot joint, a distance not less than the distance from the pivot joint to the outer ends of the jaws, and the leg members are laterally separated between the pivot joint and the guide means.

ARRANGEMENT IN HANDTOOLS, SUCH AS PLIERS, PINCERS AND THE LIKE BACKGROUND OF THE INVENTION The present invention is concerned with handtools, such as pliers, pincers and the like, having two leg members pivotally fastened together by a rivet or a screw etc. at a pivot joint located between the jaws and the handle of the tool.

When concerning handtools of this description it is generally sufficient to guide the movement of the jaws by means of a good fit between those portions of the pivot joint which move against one another as the tool is opened or closed. In this manner sufficient accuracy is obtained in the jaw movement of the tool for most tasks, irrespective of whether the jaws are designed to grip, bend, clip or to fulfill some other function. However, when working in confined spaces or on workpieces difficult to reach it may, at times, be desirable to use a tool in which the pivot joint is less bulky, i.e. a pivot joint of very small width and thickness. In pivot joints of such slender dimensions the size of those portions of the joint which move against one another are, of course, also small. Hence, if the tool is to fulfill unchanged requirements of negligible play in the pivot joint it is necessary to set closer tolerances in said pivot joint, especially as excess play in the joint may cause the members to be positioned obliquely relative to the intended plane; i.e. so that the jaws are somewhat overlapping. Moreover, tools of this category are often intended to grip, clip or in some other manner handle very small objects, resulting in a demand for increased precision in the play-free movement of the jaws.

SUMMARY OF THE INVENTION The object of the present invention is to provide a handtool of the described type which in spite of presenting a slender pivot joint also presents jaws which are guided axially with great precision.

The object of the invention is achieved in that the one leg member of the tool presents a recess located between the pivot joint and the handle, in which a portion of the other leg member is accommodated, at least when the leg members are located in a position in which the jaws are intended to act upon the workpiece; the recess and the portion accommodated therein being adapted as a guide means to reduce any axial play occurring between the jaws as a result of a poor fit between the contacting portions of the slender pivot joint.

In this manner an assurance is obtained against undesirable axial movement of the jaws in those mutual positions of the leg members which are of particular importance for the intended task; for instance within that area of movement of the leg members of diagonal cutting nippers which corresponds to the position of the jaws when clipping wire of the dimensions for which they are designed. Further, this high degree of accuracy is obtained at reasonable manufacturing costs; especially if the complementary guide means is positioned at a much greater distance from the center of the pivot joint than are the outer ends of the jaws. If, for instance, the guide is positioned at a distance from the center of the pivot joint which is twice as great as that at which the ends of the jaws are situated then in principle twice as much tolerance in measurements can be allowed when machining the surfaces of the guide means as when working the edges of the jaws or other cooperating portions. In order to provide for a corresponding lack of play in handtools not provided with the auxiliary guide means according to the invention it would be necessary for the fit between the mutually engaging portions of the joint to be so perfect as to be inconsistent with the ease of movement of the leg members and low manufacturing costs.

DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the invention will now be described in detail with reference to the accompanying drawing.

FIG. I is a perspective view ofa pair of single joint diagonal cutting nippers.

FIG. 2 shows in enlarged scale the auxiliary guide means, i.e. the recess in the one leg member and the portion of the other leg member accommodated therein.

As can be seen from FIG. I the two leg members 1 and 2 of the tool are pivotally connected together with a rivet 3 in the pivot joint 4 of the tool, designed for said rivet. In the shown embodiment the tool is a pair of diagonal cutting nippers having ajaw member 5 on each leg member I, 2; the jaw members Seach presenting a cutting edge.

The one leg member 1 is provided with a recess 6 in which the portion 7 of the second member projects and in cooperation with the recess acts as a guide when the jaws are closed or almost closed i.e. within at least an area of movement adjusted for clipping such wire as that for which the tool is dimensioned. In the recess 6, which is substantially U-shaped in cross section, the slide surfaces of the guide comprise two flat, opposing surfaces disposed parallel to the plane of rotation and which cooperate with flat, parallel surfaces disposed on the portion 7 of the second member accommodated in said recess.

As can be clearly seen from FIG. 2 the two surfaces on the portion 7 accommodated by the said recess have been provided with two shoulders 8 projecting outwards from the leg member; thereby facilitating the machining of the surfaces to desired accuracy in dimensions.

When the jaws of the tool shown in FIG. I are closed the leg members extend from the pivot joint 4 parallel to one another I in a direction towards the handle 10 through a distance which is substantially longer when measured from the center of the rivet 3 than the distance of the points of the jaws from the same point. The auxiliary guide 6, 7 is positioned where the jaws cease to extend parallel to one another and diverge to form the handle of the tool. The advantages with this positioning of the guide means at a relatively long distance from the pivot joint has previously been discussed and it need only be mentioned at this point that the design of the members as such is also advantageous since the portion of the tool where the leg members extend parallel to one another allows the jaws of the tool to be inserted further into confined spaces that is usual in tools of the described type.

The handtool, which should be self-opening to a normal starting position for working operations can, as shown in FIG. I, suitably be provided with a spring 9 in the recess 6. The spring thus biases the portion 7 accommodated in the recess from the closed position of the jaws back to a predetermined starting position.

The invention is naturally not restricted to the shown and described embodiments but can be varied arbitrarily within the scope of the following claims.

Iclaim:

l. A handtool comprising a pair of leg members pivotally attached together intermediate their ends by a pivot joint having a pivot axis, said pair of leg members having mutually opposed jaws disposed on one side of said pivot joint for acting on a workpiece and handles for operating said jaws disposed on the other side of said pivot joint, and

guide means carried by said leg members for precisely aligning said jaws laterally with respect to one another, said guide means being located on the opposite side of said pivot joint from said jaws and being spaced from said pivot axis a distance not less than the distance from said pivot axis to the outer ends of said jaws, said guide means comprising a pair of guide faces disposed on opposite sides of one of said pair of leg members and a recess in the other of said pair of leg members, said recess having a pair of guiding surfaces for receiving and closely accommodating said guide faces at least when said jaws are in position to act upon said workpiece, said leg members being laterally spaced apart over an elongated portion of their length between said pivot joint and said guide means to prevent contact therebetween along said elongated portion.

laterally spaced from said one leg member to enhance interaction with said guiding surfaces. 

1. A handtool comprising a pair of leg members pivotally attached together intermediate their ends by a pivot joint having a pivot axis, said pair of leg members having mutually opposed jaws disposed on one side of said pivot joint for acting on a workpiece and handles for operating said jaws disposed on the other side of said pivot joint, and guide means carried by said leg members for precisely aligning said jaws laterally with respect to one another, said guide means being located on the opposite side of said pivot joint from said jaws and being spaced from said pivot axis a distance not less than the distance from said pivot axis to the outer ends of said jaws, said guide means comprising a pair of guide faces disposed on opposite sides of one of said pair of leg members and a recess in the other of said pair of leg members, said recess having a pair of guiding surfaces for receiving and closely accommodating said guide faces at least when said jaws are in position to act upon said workpiece, said leg members being laterally spaced apart over an elongated portion of their length between said pivot joint and said guide means to prevent contact therebetween along said elongated portion.
 2. A handtool according to claim 1, wherein each of said guide faces is carried by a shoulder extending laterally outwardly from said one leg member whereby said faces are laterally spaced from said one leg member to enhance interaction with said guiding surfaces. 